SOUTH BEND — Indiana convenience stores and gas stations seeking the right to sell cold beer to customers filed a federal lawsuit Tuesday aimed at lifting a ban on the practice.

The Indiana Petroleum Marketers and Convenience Store Association argued Indiana's law is arbitrary and discriminates against grocery and convenience stores.

The lawsuit, filed in U.S. District Court in Indianapolis, contends Indiana is the only state that regulates the temperature of beer being sold. It says the practice started in 1963 and there's no legitimate purpose for the restriction. In 1963, Indiana began allowing liquor stores to sell chilled beer.

"In reviewing the history, it became more and more clear to us there really was not a rational basis for the current law," said Scot Imus, the association's executive director. "The fact the law says pharmacies, convenience stores and grocery stores are capable enough to sell the product warm, then it gets rather arbitrary about what temperature it can be sold at. When you change the temperature, it doesn't change the alcohol content."

The lawsuit names the state, the Indiana Alcohol and Tobacco Commission and its chairman, Alex Huskey, as defendants and seeks declaratory judgment and injunctive relief. Spokesman Brandon Thomas said the commission would not comment on pending litigation. Indiana Attorney General Greg Zoeller said he will argue that the law reflects the wishes of state lawmakers.

"This subject has been debated in the Legislature for a number of years, and it will be the state's position that the Legislature is the proper forum for any changes to our laws and not the courts," he said.

John Livengood, president of the Indiana Association of Beverage Retailers that opposes any change in the law, said he expects the courts to side with Indiana, saying states have the right to determine how alcohol is sold.

"It's a direct attack on Indiana's policy," he said.

The lawsuit was filed specifically on behalf of Wayne County resident Steven Noe and three Indiana Petroleum Marketers and Convenience Store Association members — Thorntons Inc. based in Louisville, Ky., Ricker Oil Co. based in Anderson and Freedom Oil Inc. based in Warsaw.

The suit argues the state of Indiana loses tax revenue when Indiana residents who live in Illinois, Michigan, Ohio or Kentucky drive across the state line to buy cold beer.

Noe bought a chilled 12-pack of Bud Light from a liquor store in Richmond on Saturday for $13.36, according to the lawsuit. He bought the same warm 12-pack from a Richmond convenience store for $10.69 and chilled from a New Paris, Ohio, convenience store for $11.76.

Imus said the fact that the convenience stores and grocery stores can sell chilled wine products is another example of how arbitrary the law is.

"We don't think the state should be in the business of picking winners and losers and allocating market share," Imus said. "Businesses that are given the authority and have met the regulatory controls requirement the state insists upon ought to be able to sell the product the way customers want it."